The present invention relates to apparatus for manipulating filter rod sections or other rod-shaped articles which constitute or form part of smokers' products. More particularly, the invention relates to improvements in apparatus for manipulating filter rod sections or the like between one or more producing machines and one or more consuming or processing machines, for example, between one or more filter makers and a filter tipping machine. Still more particularly, the invention relates to improvements in apparatus wherein a pneumatic transporting unit receives rod-shaped articles from one or more producing or supplying machines and the articles which issue from such unit are delivered to one or more consuming or processing machines while simultaneously changing the direction of their movement from axial movement in the interior of the pneumatic transporting unit to sidewise movement preparatory to entry into a processing or consuming machine.
Apparatus of the type to which the present invention pertains are installed at a receiving station where the output of the pneumatic transporting unit is converted into one or more layers of rod-shaped articles which are admitted into the magazine of a filter tipping machine or into the receptacle or hopper of another processing or consuming machine. Pneumatic transporting units are used in many tobacco processing plants as superior substitutes for conventional chargers or trays which were popular one or more decades ago. The trays are suspended from an overhead conveyor system which transports empty trays to one or more producing machines and delivers filled trays to one or more consuming or processing machines wherein the contents of filled trays are dumped or otherwise transferred into hoppers, magazines or analogous receptacles. Reference may be had, for example, to commonly owned U.S. Pat. No. 3,662,880 granted May 16, 1972 to Kochalski et al. which discloses a machine for filling trays at the discharge end of a cigarette maker or the like. The manner in which the contents of trays can be evacuated into the magazine of a packing machine is disclosed, for example, in commonly owned U.S. Pat. No. 3,672,522 granted June 27, 1972 to Wahle et al.
An advantage of a pneumatic transporting unit is that it can convey rod-shaped articles through any desired distance and at an elevated speed. Moreover, the conveyor pipe of such transporting unit can be readily guided practically anywhere above or even below the floor level to occupy space which is available in a tobacco processing plant. A sender station at the receiving end of the conveyor pipe accommodates means for admitting rod-shaped articles into the inlet of the pipe, and the instrumentalities at the receiving station are designed to accept the articles which issue from the pipe and to change the direction of movement of such articles from axial movement to sidewise movement.
A receiving station of conventional design is disclosed in German Offenlegungsschrift No. 2,641,934. This station accommodates (a) a separating unit wherein the rod-shaped articles which issue from the outlet of a pneumatic conveyor pipe are spaced apart, as considered in the axial direction, and (b) a deflecting or orientation changing unit wherein the articles which arrive from the separating unit are caused to change the direction of their movement from axial movement to sidewise movement. The provision of clearances between successive articles which enter the separating unit is desirable because this allows for unimpeded changes in orientation of articles during transport through the orientation changing unit. The separating unit comprises a braking device which decelerates successive articles, as they issue from the outlet of the pneumatic conveyor pipe, so that the speed of all decelerated articles matches a preselected optimum speed. The braking device is followed by an accelerating device which increases the speed of successive articles leaving the braking device to thus provide the aforementioned axial clearances which allow for unimpeded deflection of articles in the orientation changing unit. The latter comprises an upright duct with parallel walls which define a channel having a width slightly in excess of the diameter of a rod-shaped article. A wedge-like or cam-shaped deflector and/or one or more air discharging nozzles in the channel serve to change the direction of movement of oncoming articles from axial movement to sidewise or transverse movement. The thus obtained row of rod-shaped articles is delivered to the magazine of a processing or consuming machine.
A drawback of the just described conventional receiving station is that its capacity is rather limited. Therefore, such station cannot be used for delivery of rod-shaped articles to a high-speed packing or filter tipping machine because the requirements of these machines are extremely high. Moreover, when the pneumatic conveyor pipe of the transporting unit which delivers articles to such conventional receiving station (i.e., to the braking device of the separating unit) is clogged or the transporting unit fails to function satisfactorily for another reason, the delivery of articles to the processing or consuming machine is interrupted with attendant losses in output. The same holds true if the separating unit and/or the orientation changing unit of the just described conventional apparatus fails to operate in the prescribed manner.
As mentioned above, the requirements of modern high-speed processing or consuming machines (such as packing machines for plain or filter cigarettes or filter tipping machines) are extremely high. Attempts to satisfy the requirements of such high-speed processing or consuming machines include the provision of pneumatic transporting units with two or more pneumatic conveyor pipes each of which delivers a discrete file of rod-shaped articles to a receiving station. For example, U.S. Pat. No. 3,222,110 to Kelly et al. discloses a composite transporting unit with several conveyor pipes which serve to receive cigarettes from several makers and to deliver cigarettes to a collecting station or to a processing machine. The units at the receiving station, i.e., at the outlets of the conveyor pipes, also define several lanes or paths for the transport of cigarettes therethrough. The number of lanes corresponds to the number of conveyor pipes, and each lane receives the output of a discrete pipe. As in the aforedescribed conventional structure which is disclosed in the German Offenlegungsschrift No. 2,641,934, the receiving station of Kelly et al. comprises a separating unit which receives cigarettes from the outlets of the conveyor pipes and is located upstream of a deflecting or orientation changing unit. The total number of conveyor pipes in the transporting unit is four. The separating unit comprises an endless conveyor belt for each pair of pipes, and each belt cooperates with a first roll to uniformize the speed of oncoming cigarettes as well as with a second roll which accelerates the cigarettes advancing beyond the first roll. Each roll has two peripheral grooves bounded by surfaces whose cross-sectional area is complementary to that of the external surfaces of wrappers on the cigarettes which issue from the respective pipes. A cigarette which extends in part into a groove is also engaged by the endless belt so as to be transported at a desired speed. The peripheral speed of each second roll is higher than the peripheral speed of the respective first roll, i.e., the cigarettes which advance beyond the first rolls are caused to move apart and to establish axial clearances or gaps which are needed to permit unimpeded deflection of cigarettes during travel through the orientation changing unit. The latter comprises four downwardly extending channels serving to discharge rows of cigarettes into a common junction zone which is located immediately at the inlet of a packing machine or at the inlet of a collecting station.
The mobile parts of the separating unit in the apparatus of Kelly et al. are driven by a prime mover. The prime mover transmits torque to a first shaft which is rigidly connected with both first rolls and to a second shaft which is rigidly connected with the two second rolls. Thus, when the prime mover is on, it drives both shafts and each of these shafts drives the corresponding pair of rolls at the selected speed which is higher in the case of the second shaft. The patented apparatus further comprises photocells which generate signals when the conveyor pipes of the transporting unit are clogged; such signals are used to interrupt the delivery of cigarettes to the separating unit at the receiving station. However, stoppage of delivery of articles to a lane of the separating unit does not entail any stoppage of the corresponding portion of the separating unit and/or corresponding portion of the orientation changing unit. Thus, whenever a single conveyor pipe of the transporting unit is clogged, or whenever a single lane of the separating and/or orientation changing unit at the receiving station which is disclosed in the patent to Kelly et al. requires insepection and/or repair, it is necessary to shut down the entire apparatus with attendant extremely high losses in output. Even short-lasting interruption of delivery of articles to a high-speed processing machine creates additional problems, especially when the nature of the machine is such that the material which is processed immediately after starting must be discarded.
Another drawback of the apparatus which is disclosed by Kelly et al. is that it does not embody any means for regulating the removal of articles from the aforementioned common junction zone which receives articles from the four channels of the orientation changing unit. This, too, can create problems if the operation of one or more portions of the orientation changing unit is unsatisfactory and/or if the rate of delivery of articles to the processing machine or to the collecting station must be varied for other reasons. In fact, it would be difficult to regulate the rate of transfer of articles from the orientation changing unit to the processing machine and/or to the collecting station because such station or machine is immediately adjacent to the junction zone.